/*
 * JBoss, Home of Professional Open Source
 * Copyright 2013, Red Hat, Inc. and/or its affiliates, and individual
 * contributors by the @Posts tag. See the copyright.txt in the
 * distribution for a full listing of individual contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package at.fhj.itm11.forum.data.impl;

import java.util.List;

import javax.ejb.Stateless;
import javax.enterprise.event.Event;
import javax.inject.Inject;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;

import at.fhj.itm11.forum.data.PostDAO;
import at.fhj.itm11.forum.model.Post;

/**
 * @author Mario Kullnigg
 * @author Jürgen Kiendler
 **/

@Named
@Stateless
public class PostDAOImpl implements PostDAO {

	@Inject
	private EntityManager em;

	@Inject
	private Event<Post> postEventSrc;

	public Post findById(Long id) {
		return em.find(Post.class, id);
	}

	@Override
	public List<Post> findPostsByTopic(long topicId) {
		CriteriaBuilder cb = em.getCriteriaBuilder();
		CriteriaQuery<Post> criteria = cb.createQuery(Post.class);
		Root<Post> post = criteria.from(Post.class);

		criteria.select(post).where(cb.equal(post.get("topic"), topicId));
		criteria.orderBy(cb.desc(post.get("date")));
		return em.createQuery(criteria).getResultList();

	}

	@Override
	public void persist(Post post) {
		em.persist(post);
		postEventSrc.fire(post);
	}

	public void setEm(EntityManager em) {
		this.em = em;
	}

	public void setPostEventSrc(Event<Post> postEventSrc) {
		this.postEventSrc = postEventSrc;
	}

}
